


The Hidden Variables Theory

by siriuspiggyback



Category: The Umbrella Academy (TV)
Genre: Age Regression/De-Aging, BAMF Klaus Hargreeves, Family Feels, Gen, Mystery, No Apocalypse (Umbrella Academy), Number Five | The Boy Has Issues, Number Five | The Boy Needs A Hug, Number Five | The Boy-centric, Smart Klaus Hargreeves, Sober Klaus Hargreeves, Time Shenanigans, Time Travel, Underage Drinking
Language: English
Status: Completed
Published: 2019-12-18
Updated: 2020-01-08
Packaged: 2021-02-25 21:34:39
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 11,095
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21852274
Author URL: https://archiveofourown.org/users/siriuspiggyback/pseuds/siriuspiggyback
Summary: Something has disturbed the space-time continuum, and it's up to Five to figure out what it is.With a bit of luck, and a lot of alcohol, he might even manage to do it before he snaps and murders his siblings.
Relationships: Dave/Klaus Hargreeves, Number Five | The Boy & Allison Hargreeves, Number Five | The Boy & Klaus Hargreeves, Number Five | The Boy & The Hargreeves
Comments: 101
Kudos: 1279
Collections: Numerous OTPS Infinite Fandoms





	1. Part I: The Unknown Variables

**Author's Note:**

> shoutout to mildeamasoj for helping me with my inability to write summaries, you're a star
> 
> assumes that the apocalypse week played out slightly differently, where allison never got hurt, and vanya was never locked up

**Incident 1**

Things had been going well.

In hindsight, thought Five, that should have been his first clue. Things didn’t just  _ go right _ . Chance was a cruel and uncaring thing, something that Five knew better than most. Moments of happiness don’t just come to you, they had to be earned, they had to be bled for. So, he should have known, should have seen this as what it was: the calm before the storm. 

The first recordable instance, as far as Five was aware, occurred at 19:42 on a Thursday. He was sat with his siblings - all of his siblings, although Ben was still quite dead - picking over a huge order of Chinese take out. Diego was bitching over Klaus stealing his spring rolls, (something Klaus only did to annoy Diego, Five suspected). 

“You haven’t even eaten any of them, why are you stealing mine?” demanded Diego, hunching over his plate protectively.

“You really think that Klaus has any reason for the things he does?” Ben said flatly.

“Hey! I resent that,” said Klaus. “I have a perfectly good reason.”

“Which is?” asked Diego.

Klaus smiled. “Your reaction is just  _ too funny. _ ”

Diego gripped his knife threateningly.

“Guys, can you just behave for one night?” snapped Allison.

The air went sober at the tightness in Allison’s voice. She wasn’t usually easy to rile.

“Patrick again?” Luther asked hesitantly.

Allison put down her cutlery to massage her temples for a moment. Her siblings watched in various states of awkwardness, all remembering the loud argument over the phone earlier that day. She hadn’t been allowed to speak to Claire yet, despite attending her court mandated therapy sessions, and it had been wearing on her.

“Sorry, Allie,” murmured Vanya, touching her elbow in an attempt at comfort.

“Want me to stab him for you?” Five deadpanned.

“Don’t tempt me,” said Allison. “Sorry guys, I didn’t mean to… y’know.”

“It’s fine,” said Klaus. “Besides, I’m pretty sure I was seconds away from being brutally assaulted, so-

Suddenly, a flash of blue had everyone startling, pushing away from the table. Five and Diego both clutched a knife in hand. Klaus had ducked half under the table. 

“What is it?” cried Vanya, eyes fixed on the dazzling blue light hovering squarely over the dining table. Upon further expectation, it looked like a gash of pure light, jagged and sharp, pulsing. 

“Some sort of spatial anomaly,” speculated Five, squinting against the glare of the light.

Luther yelled, “What do we  _ do?” _

Five opened his mouth, a dozen responses already on his tongue, but then-

It was gone. No sound or sensation to announce its exit. Just… gone.

“Well,” said Klaus, voice shaking slightly as he clambered out from under the table. “That was weird.”

“What could have caused something like that?” asked Allison.

Five frowned. The energy looked almost like his own, but it wasn’t connected to him. Maybe something the commission had cooked up? He had thought that they had been wiped out, but maybe the bastards had enough left to rebuild? Or was it something new entirely? “I don’t know,” he admitted reluctantly. His head was bloated with theories, a handful of half-baked equations begging to be completely, competing for his attention.

“Is no one eating that last spring roll?” asked Klaus, effectively breaking Five’s concentration. With an eye roll, he blipped out of the room, reappearing in his bedroom. He had some thinking to do. 

  
  
  


**Incident 2**

“Uh- Five?”

Five wrinkled his nose, but kept writing; if he stopped now, he would lose his train of thought, and then he would have to waste time recovering it. Unfortunately, that voice came again, floating up the stairs, vaguely strained. “Five! It’s happening again!”

A jump, and he was at the bottom of the stairs, perilously close to the crack of cerulean light that hovered around three feet from the ground. The whole thing was maybe 6 inches wide, but the light was blinding, almost painful to look at. 

“How long has this been here?” he questioned.

“I don’t know,” said Allison, who was the only one around. “I was just walking through, and it was already there.”

So, he thought, probably longer than the first one had lasted. Interesting.

He looked at her, then at the bag of groceries in her arms, a baguette poking out the top. “Give me that,” he said.

Allison blinked. “What?”

“The bread, give me the bread,” said Five.

Frowning, Allison passed it to him.

Five snatched it from her grasp, and marched over to the anomaly. He leaned in and, with slow determination, poked it with the bread.

“Five!” cried Allison. “What are you doing?”

“Experimenting,” he muttered. The bread had seemingly passed through the opening; it seemed that it was, indeed, some kind of portal.

Allison said, “What if it- I don’t know, what if you poked it and it exploded?”

“Then we’d be dead,” deadpanned Five. He withdrew the bread, and inspected the end of it. “Hm,” he hummed, bringing his other hand up to run a finger through the grey substance collected on it.

“What’s that?” asked Allison, coming closer to squint at what was supposed to be her lunch.

Five rolled the grey matter between his fingers, before letting it drop, watching as it floated to the floor. “Ash,” he said. “It’s ash.”

  
  
  


**Incident 3**

The family were sitting down for dinner.

They did this once a week, at least. It was considered mandatory. Five had attempted to miss it before, when an equation had been particularly terrible, or a hangover particularly lingering, but someone always dragged him downstairs to eat something with the whole family involved. So, here he was, despite being deep in thought. He had been reading some literature on string theory, attempting to come up with something more concrete to explain the strange portals, but had so far been unsuccessful, something that irked him more than he would like to admit.

He thought it was a rather important task, but apparently family dinner was more important. (The  _ priorities  _ of these people were incredible.)

He stabbed into the steak with a violence that was, perhaps, not necessary. He had agreed to eat with them, though, not to play nice, so he continued to saw at his food with a pointed enthusiasm. 

“Um, mom,” said Diego slowly, “are you feeling okay?”

Grace turned from where she was making desert; the siblings had attempted to convince her to sit with them, but old habits died hard, and old coding died harder. “Yes, of course. What is it darling?” she trilled.

“Well- uh- mom, you know I love your cooking, but-”

“Oh my god,” blurted Klaus, before spitting onto his plate.

“Ugh,” said Luther, frowning at Klaus. “Christ, Klaus.”

“It’s  _ raw,”  _ said Klaus.

Luther rebutted, “Just because you don’t like rare steak, you don’t have to-”

“No,” interrupted Vanya, “It’s  _ raw.  _ It’s not even warm. _ ” _

Five blinked, and looked down at the food on his plate. The steak was unusually bloody, now that they mentioned it. 

“I- I don’t,” said Grace, expression going unnaturally still, her processors straining. “I don’t understand.”

“It’s okay, mom,” Ben said softly. “We all have off days.”

“No, I don’t- I cooked it.”

“Mom,” murmured Diego. 

“I heated the steaks to 144 degrees Fahrenheit exactly,” she stated. “I checked the temperature myself.”

The siblings exchanged concerned looks.

“Maybe- maybe your sensors need to be recalibrated,” said Klaus. And then, at the surprised looks, “What? I know things.”

“You thought that bats were birds,” Ben pointed out.

Klaus squawked indignantly, “They fly, that makes them birds!”

“Butterflies aren’t birds,” said Luther.

“Bees,” said Vanya.

Allison added, “Flying squirrels.”

“Moths!” said Diego.

“In fact, many birds are actually flightless,” Grace said cheerily.

Klaus threw up his hands in defeat. “I hate you all.”

“I’m leaving,” said Five. In a flash, he was back in his bedroom, book in hand. 

They couldn’t blame him; technically, they had all finished eating.

  
  
  


**Incident 4**

Five’s hand cramped, and he allowed himself a moment to flex his fingers, too-small hands starfishing. He had been doing a lot of writing, and yet seemed to make no progress. It was like those last few years in the apocalypse, going around in circles, goal slipping ever further from his grip. He pinched the bridge of his nose; a headache was brewing. Too much coffee? Or caffeine withdrawal, perhaps. Maybe he should have a drink, relax a little. 

He stood, and internally winced at the protest of his knees. He was younger than he had been, but even a thirteen year old would feel it if they were to write for as long as Five had. A drink, he thought to himself. He had earned it, after all.

Unfortunately, the parlour wasn’t empty as he hoped. Klaus and Diego were behind the bar, tossing the bottles there into a trash bag. Diego turned at his entrance, and nodded at him with an infuriating nonchalance. 

“What the hell do you think you’re doing?” demanded Five.

Klaus span. “Oh, Fivey! Didn’t see you there - you’re easy to miss, all tiny, no offence.”

“I  _ said,”  _ Five said, taking a threatening step forward, “what are you doing?”

“We’re emptying the bar,” said Diego. 

“And why are you doing that?” Five asked with gritted teeth.

“Sobriety, bro. Getting rid of temptation, and all that,” Klaus said, looking mournfully at the bottle of whiskey in his hand.

Five grabbed a decanter and, cradling it protectively against his chest, he spat, “You might be sober, but don’t drag me into this."

“It’s probably for the best,” said Diego, looking Five up and down. “Aren’t you a little young to be drinking?”

“I’m almost  _ twice your age!”  _

“But your body isn’t,” said Klaus, finally dropping the bottle into the trash. “And underage drinking can fuck you up. Take me,  _ pour example.” _

“I told you,” hissed Five, “I’m nothing like you.”

Klaus clutched at his heart. “You wound me,” he said.

“Not yet, I haven’t,” threatened Five, blipping through space to snag another bottle from the shelf.

“So aggressive,” said Klaus. “Really, you should-”

Five whipped around at the sudden choked sound that Klaus made, only to see his sibling enveloped in a cloud of blue.

“Klaus, are you doing that?” asked Diego.

“No, not me, I swear!” cried Klaus, holding up his tattooed palms.

Five squinted at the blue. It seemed to be thickening, focusing. “Klaus, I think you should-”

Except, Klaus was gone.

Where his sibling had been standing was a small child - eight, maybe nine years of age - standing in his sibling’s clothes, looking pale and afraid. Behind him, another child, this one looking about fifteen and vaguely stunned. They both looked uncomfortably familiar. 

“Are they- Is that-” stammered Diego.

“Holy shit,” muttered Ben, eyes too old for his tiny face. “I’m alive. I’m-”

“How- how did I get here?” Klaus asked, voice high and reedy. “Who are you?”

“Klaus,” said Diego.

“Who? How-” Klaus span, “What’s happening?” 

“Good question,” said Five.

Little Klaus looked at him for a moment, before his big green eyes went wide with recognition. “Is- Five, is that you?”

“Yes,” said Five.

“But you’re  _ old,”  _ said Klaus.

Diego snorted. 

“Time travel,” Five offered in explanation. “I’m from… the future.”

Klaus edged closer to Five. “Who are  _ they?”  _ he asked lowly.

“They’re- uh,” said Five. His dealing with children were limited, to say the least.

“Friends,” said Diego eventually. “Friends of Five’s.

“I don’t understand,” said Ben. “Don’t you remember?”

Klaus frowned. “Remember what?”

Ben took a long, shaking breath. “Oh.” Then, his hands flew to his stomach, and he went pale. “ _ Oh.  _ Um- I need to-  _ bye!”  _ said Ben, dashing from the room on legs an inch too short.

“Is he sick?” asked Klaus innocently. 

“Sort of,” said Diego.

Klaus tugged on Five’s sleeve. “Where’s everyone else? Where’s dad?”

“Out,” improvised Five. “On a mission.”

Klaus’ tiny face crumpled. “They left me behind?”

Five looked to Diego, panicked.

“Uh- only because, y-you weren’t feeling well! You had a fever - that’s probably why you’re confused,” said Diego.

“Oh.” Klaus pressed the back of his hand to his forehead. “I don’t  _ feel  _ sick.”

“Then you must be getting better,” said Five. “Anyway, I have a lot of things to do-”

“ _ Five,”  _ growled Diego, “Don’t you  _ dare-” _

“Bye,” Five said cheerily, popping out of existence.

It wasn’t just for selfish reasons (although, those were definitely a factor). Five really did have work to do, and it was getting a little more urgent with each passing minute; the anomalies were escalating. First just fractured in the space-time continuum, they had now progressed to time distortion. He could only guess at how they might evolve next. 

He took up his pen, and began calculating with a fevered sort of obsession. 

  
  


**Incident 5**

Five was awoken by a knock at his door.

He jerked upright, a light sleeper. He had fallen asleep at his desk. There was a puddle of drool on his page. 

The knock came again.

Five zapped over to the door, opening it with a strained, “ _ What?” _

Ben was stood at his door.

Despite the fact that he had not been present for Ben’s death, Five had long since come to terms with his absence. To see him now, especially to see him as a gangly teenager, was jarring. 

Ben’s face twisted remorsefully. “Klaus,” he said. “I think he’s having a nightmare.”

Five swallowed. “And?”

“And he’ll want to see a familiar face,” said Ben.

It was a reasonable request. Logical, even. Still, the thought of it made Five’s stomach turn; emotional intimacy was bad enough, but comforting an actual child? 

Five would rather eat a cockroach. Eat  _ ten  _ cockroaches. 

“Fine,” said Five, taking the time to walk to Klaus’ door. He wasn’t in any rush to get there. Ben shadowed his footsteps, like the ghost he had been. Was this what it had been like for Klaus? Constant eyes on his back?

He eased open the bedroom door.

The bed looked small in the room’s corner. (Five wondered how Diego had explained the expanded bedroom, what excuses there were for the eccentric decorations.) The bed sheets were snarled up around Klaus, who wriggled and twisted about. His pale face was screwed up tight, a sheen of sweat catching the light from the fairy lights hanging above him. He whined, the sounds thin and desperate as they escaped his teeth. 

“Klaus,” said Five.

“No,” muttered the child. “No- please,  _ please- Dad!” _

Five’s stomach turned. “Klaus!”

“He doesn’t remember his name,” hissed Ben from the shadows. “He’s just Four, remember?”

He glared at teenage Ben for a moment, before yelling, “Four! Wake up!” The words left a bitter taste in his mouth.

The boy jerked awake, a choked-off shriek escaping his mouth. He scrambled upright, putting his back to the wall, arms up over his head protectively. “Please-” he cried.

Five and Ben shared an uncertain, heavy look. It looked like it was down to him, thought Five, taking a slow step towards the bed. “Hey,” he said, voice as low and non-threatening as he could make it. “Hey, you’re okay.”

Green eyes peered out from where he had hidden behind his arms. His tears shone under the fairy lights. “Five?”

“Yeah, that’s right,” said Five, sitting at the edge of the bed stiffly. “You’re okay. Just a nightmare, right?”

Klaus sniffled. “Oh,” he said. “I thought…”

“Thought what?” asked Five.

“I thought that dad might- That it might be time for personal training,” said Klaus gravely, ears stained red. 

Five pressed down at the rage bubbling in his chest; there was no time for that now. “Dad isn’t here, remember? Just you and me, and- and my friends. No one’s gonna hurt you.”

“But… he’ll be back soon,” whispered Klaus fearfully.

“Kl-  _ Four.  _ I swear, I’m going to make sure that no one hurts you,” said Five, and, following some dusty instinct from his childhood, he took one of Klaus’ small pale hands in his own. 

“You promise?” said Klaus, eyes so damn earnest. 

“Promise,” said Five. “Now, you think you can go back to sleep?”

Klaus sat up straight at that, expression twisting with anxiety. “Wait, are you leaving?”

“I’ll just be down the hall,” reasoned Five.

Bottom lip wavering, Klaus said, “Oh, okay.”

_ Damn it all to hell,  _ thought Five. “Fine, I’ll stay. Only tonight though, okay?” he warned.

“Okay!” said Klaus, eyes bright. He tugged Five closer, and pulled the duvet up over them. Five tried to settle, even though he hadn’t shared a bed in around fifty years. 

“Goodnight, Five.”

Five sighed quietly. His hand was still being held tight. “Night, Four.”

Klaus ducked in just long enough to whisper, “It’s kind of nice, having a big brother.”

Five swallowed. “Go to sleep, Four.”

His smile glinted in the dim light, but Klaus obediently closed his eyes, ready to sleep. Five was glad that one of them could get some rest.

-

Five woke up.

Five- woke up?

He sat up fast enough to feel dizzy, blinking against the morning light. 

“You know,” drawled a voice next to him, way too close, “If I were going to lose all sense and seduce a sibling, you’re  _ not  _ who I would choose. No offence.”

“Klaus,” said Five, surprised. “You’re-”

“A bit alarmed, if I’m honest,” said Klaus. “I had the  _ weirdest dream... _ and you were in it, and  _ you were in it-” _

_ “Klaus,”  _ snapped Five. 

“But seriously, I haven’t had a dream that weird since I tried acid. And if that wasn’t weird enough,  _ you’re in my bed.” _

Five rolled out of the bed with an indignant huff. “And now I’m not,” he said. “What do you remember?”

Klaus’ brow wrinkled. “Remember what?”

“Hey, Ben!” called Five. “Come in here, would you?”

A shuffle of steps, and then a quiet, “Yeah?”

Five took a moment to appreciate the way Klaus gaped, jaw slack and eyes round. “Wha- Ben. You’re…”

“About sixteen,” said Ben, “Give or take a few months.”

“If you’re- But then- Was I…?”

“About eight,” said Ben, smirking. “Give or take a few months.”

“Oh. Oh, no,” said Klaus.

“Oh, yes,” said Ben.

Klaus groaned, and covered his face with his hands. “What did I do to deserve this? Wait, no, that’s rhetorical.”

Ben closed his mouth.

“You okay there?” said Five, not bothering to hide his amusement. 

Klaus tilted his head. “So you really did hold my hand after a nightmare, huh? That’s, like,  _ so embarrassing for you.” _

Five teleported out of the room before he could flush.

  
  


**Incident 9**

Since the distressing occurrence involving eight year old Klaus, Five had counted three more incidents. One count of time distortion - the fruit bowl had gone rotten overnight - and two more wormholes, each a little larger than the one before. This time, they had been able to glimpse through to the other side, one showing a stretch of forest, another revealing a brief glimpse of a busy street, people wearing bell-bottom jeans and long, uncut hair. 

Five had been working at an increasingly frantic pace. 

He didn’t feel comfortable with how little progress he had made. Nothing was adding up. He supposed that fact was telling in itself; everything was lopsided, bending and distorted, like the ripples in a pond after you throw a pebble in. He just needed to find the pebble. Whatever it was had to be small, but  _ wrong  _ in some way that he had yet to understand. Something that broke the rules of physics and space-time and the conservation of matter, and all the other rules that had yet to be discovered.

If he closed his eyes, he thought he could almost feel it. Something bitter at the back of his throat, something itching in his bones. Something  _ wrong _ . Something his subconscious understood better than he did.

He was halfway through reading a theoretical physics paper (juvenile and limited, and he had scribbled over several errors, despite the way the science community sang it's praises), when the thing at the back of his brain swelled and spilled over, his skin prickling. The sensation was similar to jumping, but it wasn't coming from him. 

He stood shakily. The air was buzzing with blue, burning this inside of his nostrils, making his eyes blur. What was  _ happening? _

Blue, blue, on the inside of his eyelids, and he-

He  _ grew. _

It was over as soon as it had begun, faster than he could understand it. His body had stretched and aged and become something familiar. Not quite what he was used to, but closer than he had felt in a while. 

Five rushed to the bathroom on long legs, stumbling slightly as his brain readjusted. He looked at himself in the mirror with wide eyes. 

His body looked, if he were to guess, to be around 40 years old. His jaw was scratchy with stubble, and his temples streaked with silver. He ran a palm over his face, skin faintly lined between his brows by years of frowning.

He laughed.

Gone was his baby face. He was an adult again! He would be taken seriously again!

This, he thought, deserved celebration.

But first: clothes that fit.

His frame was lanky, skinny. The apocalypse hadn't been kind, and left him with bones that jut out a little too sharply. He would be drowned in Luther's clothes, but he didn't want to think about what Klaus would attempt to foist off on him. So, he thought, Diego it was.

His brothers room was thankfully empty, so he didn't hesitate before rummaging through his wardrobe. It was sparse - Diego was still living between here and his gym - but there should be enough for Five to pick from. It was, predictably, all black, but he didn't mind too much, holding a pair of black jeans to his waist in an attempt to gauge his size.

And then there was a knife at his throat. 

"Who the hell are you?" growled a voice from behind him, "And what are you doing here?" 

"Is that how you greet all of your brothers?" snarked Five, grabbing Diego's wrist and twisting with fast, sure hands. 

Diego dropped the knife, but snagged it with his other hand before it hit the floor. "Wha- Five?"

Five turned, grinning sharply. "Hope you don't mind," he said, "but I need to borrow some clothes."

"You're-  _ old." _

Five snorted, and said, "Still looking pretty good for 68."

"What happened? Was this on purpose, or…?" ask Diego, eyes still a tad wide.

Five's expression soured. "No, this wasn't me."

There was something worried about Diego's dark eyes when he said, "It's getting worse, isn't it?"

"I'm working on it," Five said shortly.

"Well, work faster," said Diego, "or we're gonna end up in deep shit."

"I  _ know,"  _ snapped Five. His voice was low and serious, not the teenage whine he had resigned himself to. He snatched a shirt from the wardrobe, before stomping out of the room.

He swiped Diego’s favourite leather jacket before he jumped.

Griddy’s looked so much better from six foot tall.

He smiled toothily at the waitress - not the blonde one, someone new, brunette and chubby. She looked bashful in response. “What can I get for you?” she asked.

“Coffee. Black,” he said, taking a seat at the counter. 

“Of course,” she said. She leaned in, conspiratorial, and said, “Give me a minute, and I’ll make a fresh pot just for you.”

Five gave a shark smile and said, “Thanks.”

He shifted in his chair, stretching out his long limbs as he looked around the place. It was empty except for him. He reasoned that the recent shooting must have been bad for business, with bullet holes in the walls and the jukebox an unlit husk in the corner. As it was, he quite liked the damaged, broken interior - it was almost nostalgic of his youth, he thought wryly.

And then the blue came.

“No,” said Five. “No, no, don’t you dare-” His voice was already changing, pitching going higher, as he was overtaken by the blue light, limbs shrinking and features rearranging, liquid and malleable. All too soon, it was over.

“ _ Fuck!”  _ he hissed, smacking the surface of the counter with a hand that had returned to being all too small.

“Oh!” said the waitress, returning with a steaming pitcher of coffee. “Are you waiting for your dad? He was just here a moment ago…” 

Jaw clenched, Five said, “Can I get that to go?”

“Oh, sure,” she chimed, pouring the coffee. “Do you have money, or do you need to wait for-?”

“Here,” said Five, slamming some change down on the counter and snatching up the cup. As he stormed out, trying not to trip on his too long jeans, he could hear her muttering about  _ kids these days , _ and had to restrain the urge to stab something.

_ Stupid time distortions. _

He rounded the corner of Griddy’s, and sucked in a long breath, before jumping back home. 

In the privacy of his bedroom, he shucked off Diego’s now oversized clothes and redressed in the academy uniform. He tried to tell himself that it didn’t matter - after all, he was back to the same physical age he was yesterday, and he had been just fine then. It didn’t ring true.

  
  


**Incident 11**

Five was writing.

That was all he had been doing in the day since his temporary aging. Scribbling out equations and probability maps, theories and errant thoughts. Nothing was pulling together, and he had given himself a headache with all the grinding his teeth had been doing.  Needless to say, he wasn’t pleased when someone knocked on his door.

“Busy!” he yelled distractedly, pen not pausing.

“It’s just me,” said Allison, pushing the door open with her hip. Five rolled his eyes. “I’ve got something for you.”

Five gave her a glance, noting the lunch tray. “Thanks,” he said flatly.

“You have to eat, Five, or how are you going to think straight?” she reasoned.

“I’m thinking just fine,” snarled Five, marking a decimal point with a particularly vicious stab of his pen. The page tore slightly.

Allison sighed, leaving the tray on a corner of his desk. “Fine. I brought you this, too.”

Five squinted up. “A newspaper,” he noted. “Thanks.”

She shrugged, shoulders tight. “I know you’re a genius and you’ve most likely already thought of this, but I just thought I would mention-”

“Thought of what?”

Allison blinked for a moment, before unfolding the paper, laying it carefully over the scattered sheets of paper. “The front page is a story on climate change. There’s a story on me and Patrick on page four.”

“So you’re upset that you didn’t get front page?” Five said incredulously.

“What? No,” scoffed Allison, arms folded. “What I’m  _ saying  _ is that if this weird time stuff was happening everywhere, do you think the front page would be on  _ climate change?” _

Five stared for a moment, wrong-footed. “Oh,” he said. “ _ Oh.” _

“Yes, oh.”

Of course. How could he have been so  _ stupid?  _ He hadn’t even thought to consider… “We’re at the epicenter,” he said.

  
  


**Incident 11**

Five had been going about it all wrong.

That was what he was thinking as he wandered down to the kitchen in the search of more caffeine. He had been thinking about this as a purely mathematical problem - which in a way it was - but it wasn’t just that. This was a mystery like any other, and the same principles of unravelling applied here too. He had been so wrapped up in his equations, he hadn’t even considered gathering location data to predict its origin, hadn’t thought about the patterns and what they revealed. He felt like a fool, like he was arrogant and 13 and falling victim to his own hubris all over again.

So deep in his own thoughts, he barely noticed Ben and Klaus until he all but tripped over them. 

“Fivey!” cried Klaus cheerfully. “Long time no see!”

“Not long enough,” grunted Five, grabbing his favourite mug from the washboard.

“Oh, you’re hilarious,” said Klaus. “Actually, we were just talking about you. You see, Benjamin here is a little worried about his status in the land of the living, what with my status as an eight year old being a very temporary one. Got any thoughts to share on that?”

Five took a moment to answer, busy pouring a steaming cup of coffee. “What?” 

“Am I going to go back to being dead?” Ben asked bluntly.

“How the hell would I know?” said Five, taking a careful sip.

A beat.

_ Oh,  _ thought Five. Pinching his nose, he turned to Ben, who looked pale and wan. “Look, I don’t- I know that probably isn’t reassuring, but I don’t have the first clue what caused this. All I know is that it’s getting worse. Maybe you’ll stay sixteen, maybe you’ll go back to being a ghost.”

Ben nodded slowly. “So it’s just down to chance?” 

“Essentially, yes,” said Five. “The only thing I can think that could reduce the chance of you aging back…”

“Yes?” Klaus said eagerly.

“Leave. Go far away from the academy, at least until I fix this. This is ground zero. Maybe it won’t follow.”

Ben and Klaus exchanged a look. “I did want to go see the ocean,” Ben said eventually.

Klaus looked at him for a while, something unsaid in their eyes that Five had no hope of understanding. “Take Luther with you,” he said. “He needs to get out, see the world a bit.”

Ben’s face hardened. “Luther and me? You sure that’s a good idea?”

“No. Do it anyway,” said Klaus.

“You have a problem with Luther?” Five asked, only half curious.

Klaus was quick to say, “It’s a long story that we don’t have to go into right now.”

Five hummed, giving him a suspicious look. “Whatever. Ben, take Luther, go alone, I don’t care, but if you want to stay sixteen, go sooner rather than later,” he advised, before jumping back to his room, satisfied that he had done his brotherly duty for the day. 

He took another sip of coffee. It was stone cold.

  
  
  


**Incident 18**

Five had enlisted the help of Klaus, Allison, and - rehearsals permitting - Vanya, with Ben and Luther busy on their road trip. He had determined that the epicenter of the mystery phenomenon seemed to be the north side of the mansion, although they seemed to be spreading out further and further. Now, he was attempting to plot the frequency, but he needed more data first to measure it with any accuracy. Hence, help.

Allison was in the security room, keeping an eye on the cameras, whilst Klaus was camped out in the courtyard, and Vanya checked out the blind spots. They had dug out some walkie-talkies back from their mission days, and they contacted him whenever they noticed an anomaly (or, in Klaus’ case, whenever he found himself bored).

“Five! Come in, Fivey!” crackled Klaus’ voice.

Grabbing his radio, Five bit out, “Klaus, if you’re just going to tell me about a bee you saw, or a bird, I  _ swear-” _

“Hey! First of all, it was  _ two bees,  _ and-”

Huffing in defeat, Five jumped, reappearing in the courtyard. “Klaus, the whole point of the radio’s was-”

Klaus waved his hands. “No, look, it was for real this time!” Klaus said, turning Five around to see the wormhole behind him.

Five swore.

If he had any doubt that these occurrences were escalating, he was certain now; the rift was about 4 feet tall and 3 feet wide. On the other side, in the dim evening light, he could just make out sounds of men laughing as they staggered drunkenly down the street. The shop signs were all in a foreign script, but from the smell of the restaurants, he guessed it might be somewhere in Cambodia, the scent bringing back one of his trips with the Commission.

“Wait,” said Klaus, “shit, is that-”

“Klaus?” said Five, uncertain at the strange, urgent undercurrent in his sibling’s voice.

“I know this place. I know that night, but- I should be there. I was there, Five, why aren’t I-”

Five squinted. “An alternate universe, perhaps? I don’t know. But when were you-”

“So- So what, it’s a world where I never went back in time?” stammered Klaus, eyes fixed on the window into the past.

“The briefcase,” Five said in realisation.

“A world where I never met Dave?” he whispered as the gaggle of men broke into a slurred, half shouted song, turning the corner out of view. 

“Who?” asked Five, feeling more lost by the minute.

“Fuck. Fuck,” gasped Klaus. He looked at his brother with wide eyes for a moment, blurting, “Tell Ben I’m sorry.”

“For what-” began Five, and then-

Klaus hurtled at the portal, was swallowed and spat out on the other side.

_ “Klaus!”  _ shouted Five. 

He could see, through a quickly narrowing gap, as Klaus picked himself up off the floor, brushing his trousers down with shaking hands. “See you, Five,” he said.

“Klaus, get back here!” Five demanded, just as the wormhole sewed itself back together.

And Klaus was gone.

  
  
  



	2. Part II: The Known Variables

**Notes for the Chapter:**

> tw for mentions of death/suicide, underage drinking, and bad science

**Incident 18, part ii**

“Fuck,” said Five, and then, because that seemed the only appropriate response, he yelled, “ _ Fuck!” _

How had he let this happen? How had he lost a sibling? He had only  _ just _ averted the end of times, and already he had fucked up!

“Fuck!”

He ran his hands through his hair, feeling wild and manic, unwilling to accept the situation he had created. What did he do? 

How was he going to tell  _ Ben? _

He fumbled with his radio with numb fingers, and croaked out, “Family meeting, now.”

Five was vaguely aware of the wary response from his sisters, but he couldn’t quite process the words. Instead, he jumped back into the mansion, feeling strange and off kilter. He could feel his heart pulsing in his throat, adrenaline running, muscles itching to move, run, but with no action to take. 

“Five?” 

He span, feeling woozy at the motion. “Vanya,” he said, mouth dry.

“What- What’s going on?” she asked, brow furrowed.

Then, the fast, heavy steps of Allison raced towards them. When she burst into the room, her face was pinched with worry. “Five? What is it?”

Five swallowed, and pushed it all down. “Klaus is gone,” he said evenly.

“Gone? What do you mean, gone?” Allison asked sharply.

“Gone. He jumped through a wormhole. Gone.”

“Through- What? Why would he do that?” said Vanya blankly.

Five heaved a long sigh before jumping, landing behind the bar and reaching for a bottle stashed underneath behind a couple of old ornaments. He had made sure it was hidden, not wanting to tempt Klaus’ fragile sobriety. That wouldn’t be necessary now, Five thought dryly, taking a swig straight from the bottle and slamming it onto the bar. “How the hell would I know,” he spat.

“He must have said something, though,” Allison said, wandering closer, arms wrapped loosely around herself.

“Klaus wouldn’t just… Would he?” asked Vanya, unsure.

“Clearly he  _ would.  _ Since he just did.”

Allison leant against the bar, skin ashy. “I don’t understand. He must have said  _ something!” _

“It was somewhere he had been before,” said Five. He took another shot from the bottle, relishing in the cold burn. “Somewhere from his own past.”

“Is that dangerous? Like, what if he met himself? Wouldn’t that cause a paradox or something?” said Vanya.

Five shrugged. He had thought that he understood time, understood physics and complex theories, but now he could see that he was the biggest fool of them all. He couldn’t figure out the problem. Couldn’t figure out how to save his siblings.  _ Idiot. _

“But he can come back, right? If he just went back a few years, he could just live those few years and come back to us, yeah?” Allison suggested - begged, really, hoping for a reason to hope.

He closed his eyes for a moment. “It wasn’t our timeline. He said that he was supposed to be there, but he wasn’t. He might see us again, but not this version of us.”

“But… But I told Claire that she could meet him,” whispered Allison.

He heard a hitch of breath, and looked up in time to see Vanya cover her face, shoulders shaking.

“Van,” said Allison, pulling her into a hug.

Five looked away. He couldn’t watch. Couldn’t see what he had caused.

Maybe it was cowardly to leave, but he thought he was okay with being a coward.

  
  
  


**Incident 19**

Five stared at the amber liquid at it swished around the bottle. It held a significantly smaller volume than it had an hour ago, and it was enough that the inside of Five’s head was rocking and moving and swimming. The floor was a vague concept, despite the fact that he was lying on it. He moaned. His alcohol tolerance was pitiful. 

With numb fingers, he plucked the eye from his pocket, a remnant from a mystery that he had already solved. A souvenir of past mistakes. He rotated it until the pupil was staring at him, a black abyss, soulless and blank.

He wondered what Delores would have said if she could see him. Something scathing, probably. If she had been willing to speak to him at all.

_ I know, _ he thought to himself, biting the inside of his cheek to slow the onslaught of regret. The only thing he could do now was to fix the situation, and save the siblings he still had, but now he was drunk and slow and he couldn’t even do  _ that.  _

And Ben.

Oh, God,  _ Ben. _

He didn’t even know. As far as he was aware, Klaus was still here, half helping and half distracting Five from his work. Had Allison or Vanya called him? Doubtful. Neither had much practice with the whole ‘communication’ thing, or the ‘healthy family’ thing. As the eldest, it should have been his responsibility. As the  _ person responsible,  _ he should be the one to call them. 

With a groan, Five rolled onto his front, and pulled his limbs underneath himself, his head lolling on the floor. It would have been easier, except for how everything was spinning. It took a few false starts, but he eventually managed to push himself up onto his knees, and then, leaning heavily against the wall, onto his feet. 

His stomach lurched uncomfortably, and he took a full minute to breathe out of his mouth slowly and will it to stop. 

The phone. He had to stay on task. Just get to the phone.

So, down the stairs. 

Five stumbled his way down the hall, shoulder dragging against the wall. His head felt heavy and alien, drooping on his neck, unable to balance. His toes stubbed against the inside of his shoes as he misjudged the floor, scuffing the leather when it scraped the floorboards. He felt like he might be dreaming.

Maybe he had drank too much.

At the stairs, he clutched the hand rail, taking each step with exaggerated care. The steps seemed the waver, and each movement forward felt like he might drop into a vast void, his feet never finding ground, but he persevered. 

Until he fell.

The moment between the fall and the landing seemed to skip by him entirely; he was half sure that he had fallen through a wormhole and been spat out at the bottom. He blinked, puzzled, and then groaned when the pain hit, a distant throbbing where his knee must have collided with something on his decent. He squinted at the offending limb, and it seemed to glare back at him, hot and tender, bruise already forming. 

The phone. The  _ phone, stay on task!  _

He gathered himself up on unresponsive legs, and pushed forward to where the phone was hanging on the wall.

It was funny, he thought, that he had memorised the number of the motel that his brothers were staying at without even trying. Funny, because that was something a  _ smart person  _ would do, and Five, as he recently had discovered, was  _ not  _ a smart person.

It took a couple of attempts before he could dial the number correctly, mostly because his eyes weren’t focusing properly, the numbers blurring and swirling. With the number and extension finally punched in, he waited as the phone  _ rang and rang and rang _ , the sound echoing in his brain unpleasantly, only to cut off mid ring.

“ _ Hello?”  _ a polite voice came down the line.

“Ugh,” muttered Five, “not  _ you.  _ I need to speak to the other one.”

_ “Wha- Five? Is that you?”  _ said Luther.

Five huffed. “Obviously. Now, Ben, please!” he said, the words coming out less distinctly than he would like.

_ “Are you drunk?” _

“Luther!” said Five, cheeks burning red, “If you don’t put Ben on the phone right now, I sw- I swear to God, I’m going to kill you.  _ Kill you.  _ I’ve killed, like,  _ so many people,  _ y’all don’t know, and I’ll-”

_ “Okay, okay!”  _ interrupted Luther. 

The phone make some strange crackling sounds as it changed hands, and Five wrinkled his nose at it, the pop of the speaker making his brain hurt. 

Then, a different voice, a wary,  _ “Hello?” _

“Ben! Finally,” said Five.

_ “Uh- Hey, Five. Everything… okay?”  _ said Ben.

“No,” he replied petulantly.

_ “What’s wrong?” _

“I’m dumb,” blurted Five.

There was a brief pause before Ben said,  _ “Right. Um. Why?” _

“I lost Klaus,” Five admitted miserably.

_ “You- You lost Klaus? What do you mean, you lost Klaus?” _

“‘Cause I’m  _ dumb,  _ and Klaus is  _ dumb,  _ and he went through the thingy, the- the wormhole thing, and then it disappeared like-  _ woosh,  _ gone.”

_ “What? He- Christ, okay, we can be there in like, a few hours, just- Oh fuck, yeah, we’re leaving now, okay? Are Allie and Vanya there? Do they know? What about Diego?” _

Five felt his stomach plummet. “Oh, shit,  _ Diego!  _ I didn’t- okay, okay, shh, I’m gonna call Diego now,” said Five. Stupid, stupid Five.

_ “Wait, don’t- you sound pretty drunk, maybe you should-” _

“Buh-bye!” said Five, slapping the handset onto the hook a few times before checking that he was back to the dial tone. “Diee-gooo,” he hummed to himself as he keyed in the number for the gym. “Stupid Five.”

The ringing cut out and an answering voice said, “ _ Al’s place.” _

“Al’s? I don’t want Al’s, I want Diego’s,” said Five, frowning.

“ _ Diego’s? Jesus, when is that dumbass going to get his own phone? Not his goddamn secretary…” _

“Diego!” demanded Five. “Diego, Diego, Dieeego!”

_ “Since when does Hargreeves have a kid anyway?” the man muttered distantly, and then, “Hey! Phone for you! And next time I have to play secretary-” _

_ “Yeah, yeah, _ ” Diego’s voice echoed tinnily down the line.  _ “You say that every time.” _

_ “This time I mean it!” _

_ “Just hand me the phone, would you? Who is it, anyway?” _

_ “Some kid.” _

_ “Kid? Who- oh.”  _ Then, sounding much closer, Diego said _ , “Five, that you?” _

“Diego! Finally!” said Five. He had almost fallen asleep waiting, eyes fluttering shut without his permission.

_ “Yeah, what’s up?” _

“Uh…” Five paused, squinting. The thought had run away from him.

_ “Wait, hold on - are you drunk?” _

“No,” lied Five.

Diego sighed.  _ “I’m hanging up.” _

“No, no, it’s important!” said Five.

_ “What is?” _ Diego snapped.

“It’s Klaus!” 

A beat. “ _ Klaus?” _ said Diego, voice tense.

Five hummed an affirmative. Hadn’t he already had this conversation? Maybe he was in a timeloop, doomed to repeat this confession over and over, penance for his sins.

_ “Five! What about Klaus?” _

“Gone,” said Five tiredly. “All gone. All my fault.”

_ “Gone? I d-don’t- Okay, look, I’m coming over. Don’t go anywhere, okay?” _

“Five? What are you doing?”

This was a new voice, coming from a new direction. Five made an uncoordinated turn. “What?”

Allison was stood with her arms crossed. “What are you doing?”

“Diego,” said Five, blinking dolefully.

“Wha- Oh, shit!” Allison darted forward to tear the phone from his hand. Five pouted at the rudeness of it. “Hi - yes, yeah… I was just about to call- no, it- Fine, I’ll explain when you get here, okay? Yeah…”

At this point, Five had zoned out, distracted by the ash falling onto his shoulders, catching in his eyelashes. He wasn’t quite sure where he was; Allison’s voice was at war with the familiar smell of death and ruin. Five’s hazy eyes tracked the path of the ash upwards to the portal that had opened up above his head, a metaphorical dark cloud, and huffed an aborted laugh. 

  
  
  


**Incident 20**

Five awoke to a throbbing in his head, and a matching ache on his knee. His mouth was dry and foul-tasting, like he had vomited - and maybe he had. The last few hours were a hazy smudge in his memories. He was lying on something too soft. One of the couches, maybe.

The shrill sounds of arguing were drilling into his skull.

“Would y’all  _ shut up,”  _ Five hissed, pinching the bridge of his nose and wincing at the pulsing ache. 

“Oh, look who’s awake,” said Diego, voice sardonic. 

“Unfortunately,” said Five. He braced himself, and then struggled upright, his stomach protesting the movement. 

The smell of coffee had his eyes peeling open. Vanya was stood close by, a mug held out in offering. Five grabbed it and practically inhaled the lukewarm coffee.

“Maybe that’ll sober you up,” muttered Ben. He was often saying stuff like that, small, biting remarks, forgetting that he could be overheard. 

Five groused, “I am sober.”

“Good,” said Luther. “Because we need you to fix this.”

“Fix what?” said Five.

“Klaus. All the weird stuff going on,” Allison added.

“I can’t  _ fix  _ any of it.”

“This isn’t the time for a crisis of confidence,” said Ben, voice pinched. “Klaus is out there somewhere, with no way back, and-”

“I don’t know how! This shit is  _ complex,  _ you have no idea how complex, I can’t just summon up the right portal back here-”

“Then you better figure it out,  _ fast,”  _ snapped Ben, his too-young face red. “I’m not losing Klaus, I can’t-... Please, Five.”

Five took a slow breath. He had always held a weakness for Ben, whom he had always regarded as a younger brother, even before he had  _ become _ younger. He was loathe to deny him anything, particularly when he was looking at him with a pained mixture of hope and desperation. “Okay. Okay. I’ll get back to work.”

He felt his siblings eyes following him as he lurched out of the room, back up towards his bedroom and all his futile calculations.

(If he passed their gravemarkers on the stairs - six of them in a neat row, carefully built by his thirteen year old hands, ravaged by dust storms and torrential rains but still standing stubbornly, where he would pilgrimage for their birthdays without fail, even when he wasn’t sure that his calendar was accurate at all - if he passed them on the stairs, he didn’t look. He didn’t.)

  
  
  


**Incident 21**

  
  


Five’s hand cramped.

He had spent the last half hour diligently plotting out every known incident chronologically, attempting to accurately calculate its rate of increase, in hope of reverse engineering his way back to the trigger. It was tedious work, but he didn’t allow himself to slack. 

_ “Five!” _

His pencil nib snapped, leaving a sharp dent in the paper. “What?” he yelled back.

“There’s a huge-ass portal opening up!” yelled Diego.

“Jesus,” huffed Five, teleporting down towards the bottom of the stairs. From there, he could see a vague blue glow emitting from the doorway, his siblings gathered around it. As he rounded the corner, he could see that it was the biggest yet, a blue tear spanning from wall to wall.

“Get behind me!” bellowed Luther, throwing one meaty arm across Five’s chest. 

Rolling his eyes, Five said, “Don’t be so dramatic. Just don’t get close, you’ll be fine.”

“What if something came through, though?” said Vanya, squinting at the glaring blue light. It seemed to be pulling itself apart, leaving a gaping space that stretched further and further.

“Like what?” said Diego. His hands twitched towards his knives.

Any more speculation was cut off when the portal tore open, providing a window through their reality and into another.

It was like looking in a mirror. 

Well, not  _ exactly,  _ but almost. A funhouse mirror, maybe - a distorted view of something almost familiar, stretched into something alien. 

"What-" said Luther, just as Not Luther said-

"How-"

The pair both choked off, blinking. 

Five took a step closer, inspecting their counterparts. They were gathered in an identical mansion, at what looked like the same time, the same day. But the people marked their universe as other.

Not Luther stood in front, arms spread wide protectively; normal arms, connected to a proportional body. Standing opposite his giant of a brother, the contrast was staggering. 

Not Diego was flanking him, still dressed in all black, but the large scar across his temple was missing, as were his knives. He looked softer, somehow, less jagged. His eyes were wide.

There were no discernable differences between Allison and Not Allison, make-up tasteful and heels high. The only change was the little girl who she had positioned herself in front of. Claire, Five assumed.

Not Five was observing them in turn, his gaze sharp, although the discerning expression fit better on his thirty year old face. He looked young to Five, and not just in age, but in naivety. His counterpart still had some childlike curiosity in the way he watched them, something that had been burned out of Five decades ago.

Not Ben stood by his side, older than Five had ever seen his own version of his brother alive. A portrait of what could have been.

Not Vanya was possibly the most similar, except for her shorn hair and a row of piercings in her left ear. There was also a subtle confidence to the set of her shoulders, the tilt of her chin, her open staring. She didn’t seem cowed by their attention.

(And Klaus- 

It seemed that Klaus was just as missing from their parallel dimension as he was for Five’s.)

“What is this? How is this possible?” said Not Five, slowly shaking his head, eyes on his younger, older self.

Five waved at his siblings in an attempt to de-escalate the tension. “It’s a long story,” he said. “I’m still working out the details.”

Diego snorted. “That’s an interesting way of saying that you don’t know.”

Five spared him a cutting glace. “Here’s what we do know: something has caused a disruption in space-time. We’ve been experiencing the effects of that - wormholes, time dilation, time reversal - for the last few days. The portal should close soon, and you won’t see us again.”

“Hold on, wait,” said Not Diego, brow drawn low, “How are you and Ben kids?”

“We’re not-” Five interrupted himself, heaving a sigh. “As I said, a long story.”

Allison breathed out  _ Claire,  _ too low to be intentional. Five shot Vanya a meaningful look, who gave a nod before taking Allison’s hand, a soothing gesture.

“Holy shit, you did it, didn’t you?”

Five’s head snapped around to meet his own stare. “I’m sorry?”

“You time travelled,” said Not Five, taking a step forward. His expression was something like awe.

“Sure did,” Five laughed humorlessly. “So this is- what, this is a universe where I never made that jump?”

“This is some  _ It’s A Wonderful Life  _ shit,” muttered Allison shakily. 

“So- it’s all my fault then? I ruined everything with some stupid mistake I made at thirteen?” Five continued, voice going shrill, a hysterical edge to it. His eyes looked manic above the dark shadows of sleeplessness. “If I hadn’t ran out, Ben never died? And Luther never got hurt? Allison still would have her kid, everything would be  _ hunky-fucking-dory?” _

“Five,” said Vanya, reaching out to lay a hand on his shoulder, but he shrugged her off.

“Where’s Klaus?” said Ben.

Both groups turned to Ben, startled. 

“If you haven’t had any of this time travelling shit,” said Ben, mouth pinched, “where’s Klaus?”

A beat of silence. The Not Hargreeves seemed to look between themselves for a moment, something unsaid being communicated. Eventually, it was Not Ben who volunteered, “He’s dead.”

Five felt like the air had been punched out of his lungs. 

“What?” demanded Luther. “What does that mean?”

Not Vanya, looking down at her own feet, said tonelessly, “He killed himself. When we were twenty.”

“N-No, Klaus wouldn’t do that,” stammered Diego.

“Why, why would he- Ben?” said Vanya, dark eyes wide and wet.

Ben swallowed noisily. “If I hadn’t been there… If I hadn’t died, he would have been all alone.”

Five clenched his hands into fists so tightly that his nails bit into his palms. 

“Does that mean- Is Klaus alive, where you guys are?” Not Diego asked roughly.

Five said, “We don’t know. Maybe. We… We lost him.”

“It’s closing,” said Not Five urgently, eyeing the way the blue light was eating away at their window like flame across paper, racing down to the end.

“If you find him,” said Not Ben suddenly, “your Klaus. Can you tell him- tell him I’m sorry?”

Ben inhaled sharply. “Yeah, we will. Promise,” he replied.

“Bye,” said Not Five. “Good luck getting this shit figured out.”

“Thanks,” Five said wryly.

And then they were gone.

  
  
  


**Incident 22**

Five scribbled hurriedly. The most recent incident had drilled a sense of urgency into him; if the rate of acceleration held steady, it wouldn't be long until the tears in space time were large enough to swallow their little planet whole. 

He had to  _ fix this. _

He bit the inside of his cheek as he calculated his prediction of the first occurance, the spark that started it all, the tipped domino. His hand spasmed around his pencil.

Five looked at his answer, and swallowed convulsively.

Shit.

Shit, shit,  _ shit! _

His breaths were becoming shallow gasps.

The 24th of March. 2019. 3pm.

The moment that Five had stepped out of ‘63 and into 2019. 

Five. It had to be Five.

He laughed, the sound loud and unhinged. The irony of it was just too much. He had come here to save the world, but it was his arrival that was destroying it.

Well. Delores did say that his equations were off.

He had thought that, by projecting his consciousness into a quantum state version of himself, that he could avoid all those pesky rules about conservation of mass and matter, that he could bypass the laws of physics that had prevented him from carrying his body with him. He had been wrong. Nature was ruthless and precise, and no one could escape it. Now, it was coming for him.

There wasn't enough alcohol in the world for this. That wasn't to say that he couldn't try, though, so he jumped to the bar and fished around for his last stash of alcohol.

And, because Five had never once been lucky, he had teleported into the centre of a family meeting.

"Five? Are you okay?" Allison asked, all misplaced maternal instincts.

"Fantastic," he replied glibly, snatching up his father's whiskey.

Vanya said, "You don't look it."

Five bared his teeth in an approximation of a smile. "Don't I? Well, maybe that's because I'm ending the world."

"What does that mean?" questioned Luther.

“It  _ means,”  _ growled Five, “that it’s me. It’s me! All this shit, the wormholes,  _ Klaus,  _ it’s me, it’s my fault!” He took a long swig of whiskey.

“W- How?” said Diego.

“When I came here, to 2019, I must have- I don’t know how, exactly, but the equations were wrong, it broke the laws of physics, and the universe knows it. All of this shit has been a reaction to  _ me.  _ Like an immune system, attacking the foreign object, attempting to flush it out.”

Vanya stood, expression stormy. “So how do we fix it?”

“We don’t,” said Five.

Allison said, beseechingly, “Five-”

“We  _ can’t.  _ All I can do is… remove myself from the equation, so to speak.”

“You can’t mean-” said Luther, horrified.

“No, not  _ killing myself,  _ you idiot! I can’t be here, dead or alive. I need to  _ go.” _

“Go where?” Diego asked.

Five shrugged, swirling the crystal decanter in his grasp. “I’ll go through the next wormhole that opens up. If I keep moving through them, they should eventually lead me back to where I started, back to the timeline I came from. It won’t affect this one - you guys will be fine.”

“But what about you?” said Ben. “Without your family? In a timeline set to be destroyed?”

“Got it in one,” Five snarked.

“No, there’s got to be another way,” argued Luther, stubborn as ever. 

“Oh yeah? Why don’t you tell me, then, what’s your idea?”

“I hate to agree with Luther, but he’s right; you’re meant to be a genius, you’ve gotta be able to come up with something!” Diego said.

“You’re not listening! There is no fix for this! Either I go back, or I don’t. Those are my options,” yelled Five, chest heaving with rage and adrenaline. 

“I won’t let you,” said Vanya. Her voice trembled slightly, but her chin was held high.

Five deflated slightly. “You can’t stop me, Vanya.”

“But I have to try, don’t I?” she said. “I only just got you back.”

The two siblings looked at each other for a heavy moment, understanding running between them - both as stubborn and unmalleable as each other, both wishing things didn’t have to come to this. Wishing that they could catch a break, could have the time to just  _ be a family.  _ They were at an impasse. Vanya wasn’t willing to lose him; Five wasn’t willing to risk their lives for his own.

And then: 

The sound of a wormhole opening.

The siblings looked at where the strip of blue light was expanding, and back to Five, who eyed it with grave determination. Vanya shook her head, just once, eyes on her brother, unwavering. 

He jumped.

Despite rigorous training as a child, Five had never achieved instantaneous spatial jumps. They required him to gather his energy, to focus his mind, to push himself through the fabric of reality. He was fast, sure. But not as fast as Vanya.

“No!” she cried, flinging her hands out.

Five went down. He felt as though something had caught hold of his ankle, a firm grip that he couldn’t shake off.

He twisted, rolled, used the momentum to make another jump - not far, but far enough to escape his sisters grasp. From there, he rocked to his feet, attempted to leap through the portal that had opened up, his salvation mere inches away-

Only to be pulled back again, sharply enough that he went down hard, his nose thumping the wooden floor. His eyes watered at the stinging pain.

“Oh, shit,” said Diego.

“Sorry!” yelped Vanya.

Five, however, was familiar with working through pain, and didn’t allow it to hinder him. He scrambled upward, dodged Luther’s clumsy attempt to grab him, and weaselled past. His heart thumped wildly, adrenaline making everything more vivid. He jumped, not with his powers, but a normal, human jump, throwing his thirteen year old body towards the opening in space-time. He had been fast, too fast for anyone to grab him from behind, especially with Luther blocking Vanya’s sightline. He had made it, he thought with grim relief, he was going to make it-

Only to collide midair. A body hit his, an elbow flying into his ribs, knees knocking together. They went down in a tangle.

“Fuck!” cried Five. He heard a thud, and then the sound of the portal closing again, a final little  _ thwip  _ as it died.

“Christ on a cracker!”

Five’s heart stopped in his chest.

_ He knew that voice. _

  
  
  


**Incident 23**

  
  
  


Five shoved his way upright, ignoring the way several bruises were throbbing, and how his nose was a constant, demanding pain, wet with blood, warm and dripping down his chin. Those things could wait. 

His breath caught. “Klaus,” he choked out.

Klaus stood, dusting himself off - despite his military fatigues already being filthy - before taking the hand of the man who had followed him through. “Hi guys. Hope you didn’t miss me too much!”

A pause. The Hargreeves stood dumbly, struggling to process the turn of events.

“Um,” Klaus continued nervously. “This  _ is  _ the right timeline, right?”

“Klaus, you  _ asshole,”  _ blurted Ben, his sixteen year old voice cracking. He ran and half tackled Klaus, who stumbled, before hugging him back fiercely.

“Sorry,” Klaus said cheerfully. “Oh, uh, and this is Dave.”

“Dave, huh?” said Diego knowingly. “Well, good for you. But next time you’re about to risk your neck over some guy, give us some warning first.”

“It was kind of a spontaneous decision,” defended Klaus.

“Nice to meet you guys,” said Dave. “I kind of thought that 2019 would look different, though.”

“Sorry to disappoint,” Allison said dryly.

It was then that Klaus took notice of Five - or, more specifically, of the blood on his face. “Shit, Five, your nose! Did I do that? I didn’t mean to-”

“No, that was me,” said Vanya tightly.

Klaus blinked. “What?”

“You kind of came in halfway through something,” she explained.

“Five is trying to make a self-sacrifice play,” Diego said.

“He figured that he was causing all this time weirdness, decided that the solution was to throw himself through a wormhole,” said Ben.

Klaus said, “Huh. Following your older brothers example, hm?”

“Klaus, this is serious,” said Luther, exasperated.

“Sure, sure, sure,” said Klaus. “So, what now?”

Five shrugged, wiping his chin with his sleeve. “I wait for the next opening. Shouldn’t be long, with the way the frequency has been accelerating. I jump through, everything balances out, you’re all safe. Make sense?”

“No,” said Klaus and Dave, perfectly in sync.

“Well, it would if you were smarter,” said Five.

“No, wait, wait up a sec, I really don’t get it. Five, how exactly does your being here cause time itself to go wonky?” said Klaus.

Rolling his eyes, Five said, “The time disruption occurred when I projected myself into 2019, down to the hour.”

“But why would that cause, y’know, all this?”

Five bristled. “I don’t know, exactly. If you hadn’t noticed, the whole time travelling thing didn’t go according to plan,” he said, gesturing violently at his teenage body.

Klaus shook his head, brows drawn together. “But if you only projected your consciousness forward, like you said, it wouldn’t have violated any constants, broken any rules so to speak.”

A beat. 

Pouting, Klaus said, “What? I’m an idiot, but I’m not  _ stupid.” _

“Well, it’s the only solution I have,” said Five. “We can’t let this continue, or things will get very bad very soon.”

“I still think we should wait and come up with a better plan,” interjected Luther. 

Vanya said, “But he won’t listen.”

“Klaus?” said Dave quietly.

Klaus waved a handed, distracted. “Just thinking,” he muttered, dancing his fingers across his mouth.

“You’re out of time,” said Five. Blue light was shining from the doorway. He could see a wormhole opening up, and he was closest to it. “Please, don’t make this harder than it has to be.”

“I don’t want you to go,” said Vanya. Her eyes were damp, but her tears didn’t spill.

“For what it’s worth,” said Five, a sick feeling settling in his stomach, “I’ll miss you.”

He nodded to himself, and took a breath, walking towards the portal like he was walking to the gallows. Each step was heavy with regret. But he had to do it. For his family, if for nothing else. That was what it had all been about, hadn’t it? Saving his family?

He could see, now, through to the other side. The grey wasteland that he had called home, fires still burning, ash still falling. He could taste the copper tang of his own blood.

This was the only option, he reminded himself, hesitating, his heart thrumming, head dizzy. For his family.

“ _ Wait!” _

For the second time that day, a body collided with his. The air was knocked from his lungs, ankle twisting awkwardly under their combined weight. Klaus had him pinned, hands frantically moving over him, as if searching for something.

“Get off me!” Five roared, struggling futilely against his larger brother. He writhed, trying to get enough leverage to make a spatial jump, but then-

Klaus’ hand pulled something from Five’s pocket, something small and shiny and cold, a weight that he had been carrying for decades, and with a war cry, he lobbed it at the portal, back into the wreckage it had come from, and, with no sound, no warning, the wormhole-

Was gone.

Gone, like it had never been there in the first place.

Flushed and ruffled, Klaus collapsed backwards. “Jeez, that was a close one.”

“W-What just happened?” said Diego, voice blank.

Dave shuffled forward. “Klaus, did you just… did you just save the world?”

Klaus bounced to his feet, grinning widely. “All in a days work!”

“I don’t- the eye? It was the eye this whole time?” said Ben.

“Makes sense, right? Like, if there was already an eye sold by that shady Meritech guy, but Five  _ also  _ had the eye, that’s two eyes! That makes no sense! Like, what about conservation of matter an all that shit, y’know? You can’t have  _ two,”  _ said Klaus.

“Huh,” said Vanya.

“So,” said Diego, “does that mean Klaus is smarter than Five?”

“Absolutely not,” said Five, still staring at where his prosthetic had disappeared. 

“But he did work it out, when you couldn’t,” said Allison.

Luther agreed, “Pretty sure that makes Klaus smarter than you.”

Five counted to ten. Then, in a measured voice, he said, “I hate you all.”

“No you don’t,” said Vanya, stepping over to offer Five a hand. 

Begrudgingly, Five allowed himself to be helped upright. “I really do.”

“Just admit it,” said Ben gleefully. “You love us.”

Five glared up at the ceiling. “You’re the worst people in existence.”

“Aw, he’s just embarrassed,” cooed Klaus.

“Fuck you all,” said Five. Still, he couldn’t hide the way his mouth quirked into a sideways smile. 

The world was safe, and he got to stay with his family. He figured, it could have been worse.

(Sure, now his family will ridicule him for  _ the rest of time.  _ But, he thought, yeah... it could have been a lot worse.)

  
  


**Notes for the Chapter:**

> as always, comments really butter my toast, and i can be found on tumblr with the same username<3


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